turn up the heat on

Also, put the heat or screws
or squeeze on; tighten the screws on. Pressure someone, as in The cops turned up the heat on drivers who show signs of drunkenness, or They said they'd tighten the screws on her if she didn't confess. All of these slangy terms allude to forms of physical coercion or torture. The first dates from about 1930, the variants using screws from the mid-1800s, and squeeze from the late 1700s.